Porcupine Abyssal Plain

The Porcupine Abyssal Plain (PAP), located in international waters, is adjacent to the Irish continental margin.[1] The PAP lies beyond the Porcupine Bank's deepest point and is southwest of it. It has a muddy seabed, with scattered abyssal hills that covers an area approximately half the size of Europe's landmass. Its depth ranges from 4,000 metres (13,000 ft) to 4,850 m (15,910 ft).

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The Porcupine Abyssal Plain is a vast, relatively level stretch of seabed with a depth range of 4,000 to 4,850 m (13,120 to 15,910 ft). It has a muddy floor in the abyssopelagic zone and scattered rocky abyssal hills that rise into the bathypelagic zone forming seamounts and knolls.[2] The water at this depth is relatively stable and moving slowly towards the south and southeast. There is a downward flow of organic detritus derived from primary production in the upper layers of ocean that settles on the sea floor.

The Porcupine Abyssal Plain Observatory is a multidisciplinary moored observatory set up over twenty years ago at 49° N and 16° 30' W.[4] It is coordinated by the National Oceanography Centre and provides important time-series datasets which can be used for monitoring and analysing the effects of climate change on the deep Atlantic Ocean and its ecosystems. Since 2002, a full-depth mooring has been established. This has autonomous sensors to measure ocean temperature, salinity, chlorophyll fluorescence, carbon dioxide and nitrate.[5] A collaboration was set up in 2010 between the Natural Environment Research Council and the United Kingdom Met Office which has resulted in simultaneous monitoring of the ocean and atmosphere being made at the site.[4] The datasets are open access and available in near real time. They are uploaded to MyOcean and other websites daily for use in modelling activities. The datasets can be combined to show short-term variations on a daily or seasonal basis and longer term trends. The consequences of storms and other events can also be monitored.[5]